Begin by attaching a straight bar attachment to the low pulley machine. Next, bend over and grab the bar with your palms facing forward and just outside of your waist. Take a small step back from the weight stack and look straight ahead. Now, curl your forearms towards your shoulders until you cannot curl any further. Make sure you do not move your upper arms when curling the weight, use your elbows as a pivot point. Squeeze your biceps at the top position of this exercise and then slowly return the bar to the starting position.